This excerpt taken from the MRO 10-K filed Mar 10, 2005.
Natural Gas Marketing and Transportation Activities
In addition to the sale of our own natural gas production, we purchase gas from third-party producers and marketers for resale.
We own a 24 percent interest in Nautilus Pipeline Company, LLC and a 24 percent interest in Manta Ray Offshore Gathering Company, LLC, which are both Gulf of Mexico natural gas pipeline systems. Additionally, we own a 34 percent interest in the Neptune natural gas processing plant located in St. Mary Parish, Louisiana. The plant has the capacity to process 600 mmcfd of natural gas, which is supplied by the Nautilus pipeline system.